The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Computer networks, television networks and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer.
Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. In order to provide easier or faster information transfer and convenience, telecommunication industry service providers are developing improvements to existing networks. In this regard, wireless communication has become increasingly popular in recent years due, at least in part, to reductions in size and cost along with improvements in battery life and computing capacity of mobile electronic devices. As such, mobile electronic devices have become more capable, easier to use, and cheaper to obtain. Due to the now ubiquitous nature of mobile electronic devices, people of all ages and education levels are utilizing mobile terminals to communicate with other individuals or contacts, receive services and/or share information, media and other content.
Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. In order to provide easier or faster information transfer and convenience, telecommunication industry service providers are developing improvements to existing networks. For example, the evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) is currently being developed. The E-UTRAN, which is also known as Long Term Evolution (LTE) or 3.9G, is aimed at upgrading prior technologies by improving efficiency, lowering costs, improving services, making use of new spectrum opportunities, and providing better integration with other open standards.
In one example network configuration, mobile users communicate with each other via communication links maintained by the network. In this regard, for example, an originating station may typically communicate data to network devices in order for the network devices to relay the data to a target station. An entity referred to as a radio link controller (RLC) may manage the transmission of data of each radio bearer via different types of RLC modes. Some examples of modes may include a transparent mode (TM), an acknowledged mode (AM) and an unacknowledged mode (UM). For example, TM may be a mode in which no overhead is attached to an RLC service data unit (SDU) received from a higher layer when constituting a protocol data unit (PDU). As such, the RLC may pass the SDU in a transparent manner. In non-transparent modes like AM and UM, overhead is added at the RLC.
In AM, the AM RLC constitutes a PDU by adding a PDU header that includes a sequence number that can be used by the receiver to determine the correct order of the received PDUs, and thus, to determine whether a PDU has been lost during transmission. By setting a polling request to the RLC PDU, the transmitter may request that the receiver also provide acknowledgement for PDUs received. Thus, the receiver may request re-transmission for PDUs that were not received in order to improve efforts to provide error-free data transmission via re-transmissions when necessary. Due to the potential for re-transmissions, AM may be more well suited for non-real-time packet transmissions.
UM, unlike AM, does not provide acknowledgement for PDUs received. Thus, although the receiver may still use a sequence number provided in the PDU header to determine whether any PDU has been lost, the transmitter receives no acknowledgements for PDUs transmitted and therefore does not check whether the receiver is properly receiving transmitted PDUs. Thus, once a PDU is transmitted, the PDU is typically not retransmitted.